Knurling tool

ABSTRACT

The disclosure relates to a knurling tool of small dimensions which can located a knurl about the periphery of an outer conductor of a coaxial cable at a selected one of a plurality of fixed distances from the end of the conductor. The manual controls for effecting the selection of the location and for positioning the knurling wheels against the conductor are both one one side of the tool and protrude in a direction parallel to the wheel axes.

United States Patent Ziegler, Jr. et al. 1451 Apr. 11, 1972 [54] KNURLING TOOL 2,693,122 11/1954 Fausel ..72/107 2,618,182 11/1952 Teetor ..72/126 [721 Gm'ge wluam Cams, 3,078,744 2/1963 Bronstein ..72/124 [73] Assignee: AMP Incorporated, Harrisburg, Pa.

[22] Filed: Feb. 27, 1970 [21] Appl. No.: 15,173

[52] US. Cl ..72/125, 72/703 [5 1] Int. Cl ..B21d 19/00 [58] Field ofSearch ..72/l07, 108, 124, 125, 126, 72/703 [56] References Cited UNITED STATES PATENTS 1,399,525 l2/192l Schaad ..72/703 mand Samuel Apa, Camp Hill; Donald Elwood Heffner, Harrisburg, all of Pa.

Primary ExaminerLowell A. Larson Attorney-Curtis, Morris and Safford, Marshall M. Holcombe, William Hintze, William J. Keating, Frederick W. Raring,

- John R. Hopkins, Adrian J. La Rue and Jay L. Seitchik [57] ABSTRACT 6 Claims, 5 Drawing Figures KNURLING TOOL The invention is for an improvement in knurling tools of the I type which can be placed on a rotated thereabout.

In the copending application of George William Ziegler, Ser. No. 689,649, filed Dec. II, 1967, now U.S. Pat. No. 3,533,051, there is disclosed a method of securing a connector element to the end of an outer conductor of a coaxial cable for coaxially staking a ferrule interposed between the conductor and connector element. It has been found to be advantageous to knurl the periphery of the conductor at the location thereon where the ferrule is to be staked, in order to increase torque and pull out resistance. Where the end of the cable, which is to be prepared for the purpose of securing it to a connector element in the above mentioned manner, is in a location where space is limited, the knurling tool to be hereinafter described has been found to be of great utility and merit.

It is an object of this invention to provide a knurling tool which is rugged yet compact, so as to be useable within a small Space.

It is a further object of the invention to provide a knurling tool for the periphery of a cylindrical member which provides for selecting one of a plurality of fixed locations from the end of the conductor to receive the knurl or serrations.

Other objects and advantages of the invention will become apparent as the description proceeds with reference to the drawing in which:

FIG. 1 shows in perspective the portions of the knurling tool with the cover removed;

FIG. 2 is a cross-sectional view of the tool taken along line 2-2 'of FIG. 1 with the cover mounted thereon and showing the lower knurling wheel in its lowered position and the conductor stop member in upper position;

FIG. 3 shows the location of the knurling at the end portion of an outer conductor made by the tool with the stop member in upper position as in FIG. 2;

FIG. 4 is the same view as FIG. 3 showing the lower knurling wheel in uppennost position and the conductor stop member in lowered position;

FIG. 5 shows the location of the knurling made by the tool with the stop member in the lower position of FIG. 4.

The knurling tool of the invention comprises a pair of similar flat base plates 2 and 2 of generally equally dimensioned rectangular shape except that each of their tops is rounded off as at 4 to allow the tool to work even in cases where cable has been prebent into tight U bends. One face of each of the plates is provided with a respective longitudinally extending groove 6 and 6' which is located centrally between the sides of the base plates. At its lower end, the bottom wall of the groove 6' in plate 2 is removed, to leave a slot 7 open at the lower end. The thickness of the plate 2 is enlarged at its lower end portion such as at 8, so that when the plates 2 and 2' are assembled with the portion 8 abutting a face of plate 2, the remaining portions of the facing surfaces will be spaced from each other, as can be seen in FIGS. 2 and 4. The plates 2 and 2 may thus be secured in assembled relation by screws 9 in plate 2 cooperating with the screw threaded openings in plate 2. Tubular spacers 11 are mounted on the upper screws to bridge the space between the plates provided by the thickened portion 8 of plate 2'.

The plate 2' is provided with openings 12' and 14' equally spaced from the longitudinal center thereof. The plate 2 is equally provided with apertures respectively aligned with apertures 12' and 14, one of such apertures 12 being shown by dotted lines in FIG. 2. Identical tubular pins 16 are respectively supported at their ends in the openings in 12 and 14 of plate 2' and in the corresponding openings alined therewith in plate 2. A knurling die or wheel 18 is rotatably mounted on each of the pins between the opposing faces of the plates 2 and 2. Slidably mounted within the grooves 6 and 6' below the knurling wheels 18, is a yoke member 20. The yoke member is comprised of a block of material having smooth flat exterior walls to slidably engage the walls of grooves 6, 6'. One end portion of the block is slotted to provide a pair of arms 21, 21'

conductor and manually and its opposite end portion is shaped at one side to form a camming surface 22 and is provided with a ledge 24 which projects laterally from the opposite side thereof. The yoke member is mounted within the groove below the wheels 18, with the slot extending parallel to the surfaces between the walls of the plates 2, 2 and the open end thereof toward the wheels. A third pivot pin or axle 26 is fixedly supported between the arms 21, 21' of the yoke and supports a third knurling wheel or die 28 for rotation thereon.

A thumb screw 30 having an enlarged knurled head is threaded through the plate 2 in a direction parallel to the pins 16 and 26. The free end of the screw is tapered to form a cam portion 32 for cooperation with the cam surface 22 at one end of the yoke member 20 slidably mounted within the grooves. The ledge 24 of the yoke member extends below the end wall of slot 7 in plate 2 and is provided with a transverse threaded opening therethrough in alinement with the end wall. An adjusting screw 34 threaded into the opening provides a stop for limiting movement of the third knurling wheel 28 toward the adjacent peripheries of fixed wheels 18. For the purpose of selecting the location on the periphery of the conductor B at which the knurling is to be made, a stop plate 36 having a thickness equal to the distance S shown in F IG. 3, is provided. The stop plate is provided with a threaded opening 38 therein for receiving the threaded body of a wing bolt 40 extending through an elongated opening 42 extending longitudinally through the plate 2. The stop plate 36 is provided with an opening 44 therethrough of a diameter which is smaller than the outer conductor B but which permits the inner conductor A to pass therethrough. The plate 2 is also provided with an opening 46 of the same dimension as opening 44 and in alinement therewith when the stop plate is in its lower position as shown in FIG. 4. The plate 2 is provided with an opening 48 to permit the outer conductor B to pass therethrough in order to be positioned between the knurling wheels. If it is desired to locate the knurling on the outer conductor at a distance S from the end thereof, as shown in FIG. 3, the stop plate 36 with the wing bolt loosely threaded therein, is moved upwardly until the bolt is stopped by the upper wall of the groove 42 as shown in FIG. 2 and the bolt tightened. In this position and with the wheel 28 in its lowermost position, the end of the conductor B can be positioned against the bottom wall of the groove 6, with the conductor A extending into the opening 46. The thumb screw is then rotated to move the cam face 32 against the cam surface 22 to move the wheel 28 toward wheels 18 to firmly engage the wheels with the outer conductor. The knurling tool is then rotated about the conductor which is fixed against rotation. After retracting thumb screw 30 to permit backing off wheel 28, the tool can be slipped off the knurled end of the conductor. If the knurling is to be made at the extreme end of the outer conductor as shown in FIG. 5, the stop plate 36 is positioned as shown in FIG. 4 to form a stop against which the end wall of the conductor is moved.

Having thus described the invention with the particularity required by the statutes, it is deemed that obvious changes and modifications by persons skilled in the art will fall within the spirit and scope of the invention as defined by the appended claims.

What is claimed is:

l. A knurling tool for the end portion of a cylindrical conductor of a coaxial cable, comprising: a base, a pair of knurling wheels rotatably mounted on said base on parallel axes, a third knurling wheel, means mounting said third wheel for movement of its periphery toward the peripheries of said pair of knurling wheels, control means mounted on said base for effecting movement of said third wheel toward said pair of knurling wheels, said means mounting said third wheel being slidable with respect to said base, said mounting means and said control means including cooperatively engaging camming means for effecting movement of said mounting means, and a stop provided by said base for the end of a conductor insertable between the peripheries of said third knurling wheel and said pair of knurling wheels, said wheels being mounted on said base to provide a space between said wheels and said base to knurl the conductor at a predetermined distance from its end.

2. A knurling tool according to claim 1 in which the conductor is an outer conductor of a coaxial line having an inner conductor extending therefrom, the base having an opening to permit the center conductor to extend therethrough when the end of the outer conductor is positioned against the base.

3. A knurling tool according to claim 2 including means to selectively vary the distance from the end at which the knurling is located comprising a stop plate of predetermined thickness movable into said space between the wheel faces and the base in the path of the conductor inserted between the knurling wheels.

4. A tool according to claim 3 in which the stop plate is provided with an opening axially aligned with the opening in the base member when the stop means is in the space between the wheel faces and the base.

5. A tool according to claim 4 in which the wheels and control means are mounted on opposite sides of the base, the stop plate having a manually operated member secured thereto for moving it into a selected position and maintaining it there, said manually operated member being on the same surace as the control means.

6. A tool according to claim 4 including a cover member secured to the opposite side of the base. 

1. A knurling tool for the end portion of a cylindrical conductor of a coaxial cable, comprising: a base, a pair of knurling wheels rotatably mounted on said base on parallel axes, a third knurling wheel, means mounting said third wheel for movement of its periphery toward the peripheries of said pair of knurling wheels, control means mounted on said base for effecting movement of said third wheel toward said pair of knurling wheels, said means mounting said third wheel being slidable with respect to said base, said mounting means and said control means including cooperatively engaging camming means for effecting movement of said mounting means, and a stop provided by said base for the end of a conductor insertable between the peripheries of said third knurling wheel and said pair of knurling wheels, said wheels being mounted on said base to provide a space between said wheels and said base to knurl the conductor at a predetermined distance from its end.
 2. A knurling tool according to claim 1 in which the conductor is an outer conductor of a coaxial line having an inner conductor extending therefrom, the base having an opening to permit the center conductor to extend therethrough when the end of the outer conductor is positioned against the base.
 3. A knurling tool according to claim 2 including means to selectively vary the distance from the end at which the knurling is located comprising a stop plate of predetermined thickness movable into said space between the wheel faces and the base in the path of the conductor inserted between the knurling wheels.
 4. A tool according to claim 3 in which the stop plate is provided with an opening axially aligned with the opening in the base member when the stop means is in the space between the wheel faces and the base.
 5. A tool according to claim 4 in which the wheels and control means are mounted on opposite sides of the base, the stop plate having a manually operated member secured thereto for moving it into a selected position and maintaining it there, said manually operated member being on the same surace as the control means.
 6. A tool according to claim 4 including a cover member secured to the opposite side of the base. 